What Is UNIX Telling Me?

Some UNIX messages are very cryptic. This section tells you how to interpret common error indications so that you can quickly and easily correct what is wrong.

Usage Errors

One kind of error you might receive when entering UNIX commands is a usage error:

$ cp abc
Usage: cp [-fip] source_file target_file
       cp [-r|-R][-fip] source_file... target_file
$

Usage Means Misusage

I have seen many UNIX beginners ignore usage messages and then wonder why things aren’t working. Whenever you see a usage message, remember that it is an error message. You messed up the command, so it didn’t run properly.

Remembering that no news is good news, this error means that something is wrong and that your command didn’t execute. In this case, ...

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